(a) Field of the Invention
An exemplary embodiment of the present invention relates to a heat and water management system of a fuel cell vehicle, and more particularly, to a cooling apparatus for a fuel cell, that cools heat generated in a fuel cell stack.
(b) Description of the Related Art
In general, a fuel cell system supplies hydrogen, which is used as fuel and air as an oxidant, to a fuel cell stack, and produces electricity through an electrochemical reaction between hydrogen and oxygen. The fuel cell system is mounted within a vehicle, and drives the vehicle by operating an electric motor with electricity produced by the fuel cell stack. The fuel cell system refers to a type of electric power generation system which does not convert chemical energy of fuel into heat by combustion, but electrochemically converts the chemical energy directly into electrical energy in the fuel cell stack.
Typically, the fuel cell stack obtains desired output power by laminating several tens to several hundreds of sheets of fuel cells including a unit configured by an membrane electrode assembly (MEA), a gasket, a separation plate, or the like. Since a substantial amount of heat is generated in the fuel cell stack in addition to a fuel cell reaction, a configuration of a cooling apparatus is necessary in the fuel cell system to reduce the generated heat. The cooling apparatus includes a coolant reservoir (hereinafter, referred to as “reservoir” for convenience) that stores a coolant, and a coolant pump that supplies the coolant stored in the coolant reservoir to the fuel cell stack.
Moreover, an antifreeze fluid is used in the fuel cell vehicle as a coolant. The coolant is injected into a cooling system (also typically called “stack cooling loop” in this field) of the fuel cell stack including the reservoir when the vehicle is manufactured. The coolant may be injected in a pressing manner after the cooling system is in a vacuum state to prevent bubbles from generating in the cooling system. When the bubbles (e.g., air) are present in the cooling system when the coolant is injected, a possibility of overheating due to a coolant deficiency is increased as the coolant overflows when driving the fuel cell vehicle.
In addition, when the bubbles are present in the cooling system of the fuel cell vehicle, as described above, deterioration in efficiency of the fuel cell and cooling performance due to a local increase in temperature of the fuel cell stack may occur, coolant flow noise may occur, and moreover adverse influence such as damage of the fuel cell may occur. Therefore, the fuel cell vehicle includes an ion filter that removes the bubbles from the cooling system. The ion filter is installed within the cooling system in an engine room separately from the reservoir.
The above information disclosed in this section is merely for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.